Much attention is currently devoted to the synthesis and properties of shape-persistent macrocycles[1]. Such compounds are interesting for a variety of reasons including formation of columnar stacks potentially capable of performing as nanopores for incorporation into membranes or for the generation of nanowires[2]. Furthermore, in shape-persistent macrocycles incorporating coordination units, endo-cyclic metal-ion coordination may be exploited to generate nanowires[3], whereas exo-cyclic coordination can be used to construct large arrays of polynuclear metal complexes[4]. Shape-persistent macrocycles with reactive substituents may also be linked to other units to yield multicomponent, hierarchical structures. In the past few years it has been shown that suitably designed molecular and supramolecular species can perform as nanoscale devices and machines[5]. An important role in this regard could be played by shape-persistent macrocycles exhibiting properties modifiable by photochemical, electrochemical, or acid/base inputs. Particularly interesting are shape-persistent macrocyclic ligands containing 2,2'-bipyridine (bpy) units and their Ru(II) and/or Os(II) complexes. It is, indeed, since long known that Ru(II) and Os(II) polypyrindine-type complexes[6] exhibit suitable excitedstate and redox properties to be used as building blocks for the construction of photoand redox-active multicomponent systems[7]. As an extension of our previous studies[4,8], we report here the syntheses, the photophysical properties, and the electrochemical chracterization of the shape-persistent macrocyclic ligand 1, containing one bpy unit, and its [Ru(bpy)2(1)]2+and [Os(bpy)2(1)]2+complexes (Scheme 1). We also report the syntheses of simpler Ru(II) and Os(II) complexes that together with other previously synthesized species (Scheme 2) have been used as model compounds for interpreting the behavior of the new macrocyclic ligand and its complexes.
Ru(II) and Os(II) complexes of a shape-persistent macrocyclic ligand: synthesis, photophysical properties, and electrochemical characterization
VENTURI, MARGHERITA;BALZANI, VINCENZO;MARCHIONI, FILIPPO;
2005
Abstract
Much attention is currently devoted to the synthesis and properties of shape-persistent macrocycles[1]. Such compounds are interesting for a variety of reasons including formation of columnar stacks potentially capable of performing as nanopores for incorporation into membranes or for the generation of nanowires[2]. Furthermore, in shape-persistent macrocycles incorporating coordination units, endo-cyclic metal-ion coordination may be exploited to generate nanowires[3], whereas exo-cyclic coordination can be used to construct large arrays of polynuclear metal complexes[4]. Shape-persistent macrocycles with reactive substituents may also be linked to other units to yield multicomponent, hierarchical structures. In the past few years it has been shown that suitably designed molecular and supramolecular species can perform as nanoscale devices and machines[5]. An important role in this regard could be played by shape-persistent macrocycles exhibiting properties modifiable by photochemical, electrochemical, or acid/base inputs. Particularly interesting are shape-persistent macrocyclic ligands containing 2,2'-bipyridine (bpy) units and their Ru(II) and/or Os(II) complexes. It is, indeed, since long known that Ru(II) and Os(II) polypyrindine-type complexes[6] exhibit suitable excitedstate and redox properties to be used as building blocks for the construction of photoand redox-active multicomponent systems[7]. As an extension of our previous studies[4,8], we report here the syntheses, the photophysical properties, and the electrochemical chracterization of the shape-persistent macrocyclic ligand 1, containing one bpy unit, and its [Ru(bpy)2(1)]2+and [Os(bpy)2(1)]2+complexes (Scheme 1). We also report the syntheses of simpler Ru(II) and Os(II) complexes that together with other previously synthesized species (Scheme 2) have been used as model compounds for interpreting the behavior of the new macrocyclic ligand and its complexes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
